http://www.rug.nl/research/portal/files/41711829/cesifo1_wp6448.pdf
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/682894/Draft_Text_for_Discussion_-_Implementation_Period__1_.pdf
https://blogs.lse.ac.uk/brexit/2021/02/26/future-british-european-security-relations-are-a-matter-of-trust/
http://www.iata.org/whatwedo/Documents/economics/impact_of_brexit.pdf